Communicable Diseases and Plant Defenses

Study Notes

Communicable Diseases

Communicable diseases are illnesses caused by pathogens (disease-causing agents) that can be transmitted from one organism to another.
Examples include influenza, HIV, and tuberculosis.
Transmission routes include direct contact, airborne droplets, vectors (e.g., mosquitoes), and contaminated food or water.
Pathogens can be viruses, bacteria, fungi, or parasites.
Communicable diseases can range from mild symptoms to severe illness and death.
Prevention strategies include hygiene practices, vaccination, and quarantine measures.

Plant Defences

Plants have evolved complex defence mechanisms to combat pathogens and herbivores.
These defences are categorized as physical, chemical, and biological.
Physical defences include tough outer layers (e.g., bark, waxy cuticle), thorns, and prickles that deter herbivores.
Chemical defences involve producing toxins or secondary metabolites that are harmful or unpalatable to pests. Examples include alkaloids, tannins, and terpenes.
Biological defences can involve attracting natural enemies (e.g., predators or parasites) of herbivores, or producing proteins that interfere with the growth or survival of pathogens.

Non-Specific Defences

Non-specific defenses (innate immunity) are the first line of defense against pathogens, in both plants and animals.
In animals, defenses include the skin, mucous membranes, and secretions like saliva and tears containing antimicrobial substances.
The inflammatory response is a crucial non-specific defense mechanism, characterized by redness, swelling, heat, and pain.
Complement proteins identify pathogens and signal immune responses.
Some non-specific responses involve phagocytes (e.g., neutrophils and macrophages) that engulf and destroy pathogens through phagocytosis.
In plants, physical barriers like cell walls, and antimicrobial compounds produced in response to infection, are part of the non-specific defense.

Monoclonal Antibodies

Monoclonal antibodies are laboratory-produced antibodies.
They are identical copies of the same antibody, targeting a single antigen.
Monoclonal antibodies are generated by fusing a B cell (producing the antibody) with a myeloma cell (cancerous white blood cell line).
Monoclonal antibodies are used in medicine for diagnostic tests and treating illnesses.
They bind to specific targets (antigens) on pathogens or cancer cells.
Monoclonal antibody therapies are becoming increasingly important in cancer treatment, autoimmune disorders, and other conditions requiring targeted therapy.
Targeted therapy minimizes side effects compared to general treatments.

Description

This quiz explores the mechanisms of communicable diseases and the defensive strategies plants use against pathogens and herbivores. It covers the types of pathogens, transmission routes, and various plant defense mechanisms. Test your knowledge on health and biology!